In the last blog post, I described how to export a Plone site using collective.
Are you dealing with lots of SVN externals? Are you impatient and don't want to wait for minutes until Subversion updates all your svn:externals one after the other?
You might look at zopyx.parallel_svn_externals_updater performing update operations on svn:externals in parallel (e.g. updates all svn:externals of a Zope 2.11 checkout in 10-15 seconds).